Door operating mechanism



Nov. 26, 1940. L. D. HOULIS DOOR OPERATING MECHANISM Filed March 20, 1937 Patented Nov. 26, 1940 UNITED STATES earnr OFFICE 7 Claims.

This invention relates to new and useful improvements in door operating mechanism.

One object of the invention is to provide an improved mechanism particularly adapted for use in operating the door of a baking oven.

An important object of the invention is to provide an operating mechanism for a door which is constructed of two swinging sections, said mechanism having improved means for simultaneously swinging the sections, whereby the door may be quickly and easily opened and closed.

Another object of the invention is to provide an improved mechanism for a door of the character described, and having means for positively holding the door in its closed position, said means being arranged to compensate for slight variations in the operating mechanism due to temperature changes or other causes, whereby the mechanism operates efficiently at all times and under all conditions.

A further object of the invention is to provide an oven door constructed in two sections which swing inwardly so as to prevent excessive escape of heat when in an open position, with improved means for operating the door, the axis of the hinges of the door sections being offset from each other in a vertical plane, whereby each section travels through an arc of the same number of degrees, which assures uniform swinging of the sections and also assures positive engagement of the sections when the door is closed.

Still another object of the invention is to provide an improved mechanism of the character described, wherein each door section is secured to a rotatable sprocket and arranged to be swung when said sprocket is rotated, together with flexible means for connecting the'sprockets so that a single manual operating member may be utilized to operate the door sections; the provision of the flexible connection making for increased efiiciency under all conditions.

A further object of the invention is to provide an improved door for baking ovens including two swinging sections, one of which is offset so as to overlap the end of the other sections whereby when the doors are swung to a closed position, they are tightly closed due to the overlapping ends thereof.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawing, in

which an example of the invention is shown, and

wherein: I

Figure 1 is a side, elevation of a door operating mechanism, constructed in accordance with the invention applied thereto, 5 Figure 2 is a vertical, sectional view, taken on the line 22 of Figure 1,

Figure 3 is a horizontal cross-sectional view, taken on the line 3--3 of Figure 2,

Figure '4 is a vertical sectional view taken 10 through the doors and showing the same in their open position in dotted lines.

In the drawing, the numeral l0 designates the casing of a baking oven which is ofthe usual construction and which has an elongate opening H in its front wall. I'he opening extends substantially throughout the length of the wall and is preferably surrounded by an angular frame l2 which is formed of angle bars I! and I211. The angle bars I2 which extend vertically at the side of the opening I i (Figures 1 and 4) preferably extend throughout the vertical length of the oven, while the angle bars lZa extend horizontally only. throughout the length of the opening H, having their ends secured to the vertical bars l2. Vertical side plates 13 extend forwardly from the bars l2 and have their outer ends secured to the angular corner battens M of the oven. These side plates also support the usual loading platform 15 which is located at the lower end of the opening I l and which extends forwardly therefrom, as is clearly shown in Figure '4. The particular construction of the oven forms no part of the present invention and is, therefore, subject to variation. The above parts have been described merely for the sake of clarity.

In carrying out the invention, a door It is mounted so as to close the opening II in the front wall of the oven. This door includes an upper section A and a lower section B which have their inner ends overlapping, so that when such sections are in a vertical position, the opening is closed. The section A has its upper longitudinal edge secured by welding, or otherwise to the periphery of a rotatable shaft ll. The shaft extends longitudinally of the oven, being disposed contiguous to the upper frame bars 12a and the ends of said shaft extend through and are supported in the side plates I3. 5 When the shaft I! is rotated, it will be obvious that the section A of the door is swung. The section B has its lower longitudinal edge suitably secured to a similar shaft l8 which has its ends extending through and supported in the side plates I3. This shaft islocated adjacent the lower end of the opening I I.

Manifestly, when the sections A and B are in a vertical position, as shown in Figure 4, the inner ends thereof must overlap so as to form a tight closure and prevent escape of heat between the joints. In order to assure the close engagement of the overlapping ends, the lower section B is provided with an offset IE5 and also the lower shaft I8 which carries this section is located out of vertical alinement with the shaft H which actuates the section A. By so locating the shaft, it will be evident that before the section B can swing to a vertical position it must engage the inner end of the section A and, therefore, the section B is placed under a slight tension, as will be explained, when the door is closed. If the axes of the shafts I1 and It were in the same vertical plane, the rear or inner sections would not be under tension when the door is closed and, therefore, there would be a slight clearance between the overlapping ends of the sections which would result in escape of heat therebetween. Also by locating the shafts out of vertical alinement with each other, it is possible for both sections A and B to swing through an arc of the same number of degrees which makes it possible to operate both sections simultaneously by rotating the shafts through the same movement and at the same speed, as will be hereinafter set forth.

When the sections A and B are swung inwardly they will assume the position shown in the dotted lines in Figure 4 with the upper section A lying against the upper frame bar lza, while the lower section B is resting on the lower frame bar IZa. The length of the section B is preferably greater than the length of the section A, whereby when the former is swung downwardly its inner end will extend some distance into the oven. This will prevent the heat within the oven from rising upwardly and outwardly through the opening as the overhanging inner end of the section B forms a shield or hood when swung inwardly. Also sincethe lower shaft I 8 on which the section B is mounted lies in substantially the same horizontal plane as the loading platform I5, it will. be seen that when said section B is in its lowered position, it will form an extension or continuation of said platform, whereby the insertion of the articles to be baked is facilitated.

For swinging the sections A and B to open and close the door I6, the extended end of the upper shaft I1 is provided with a sprocket I9, which is keyed or otherwise suitably secured thereto. For rotating the shaft IT and sprocket I9, a suitable hand lever 20 is provided with a collar 2| at one end thereof and this collar is suitably fastened on the shaft II. By swinging the hand lever downwardly from the position shown in Figure 5, it will be seen that the sprocket I9 and shaft I? are rotated in a counter-clockwise direction.

The lower shaft I8 to which the section B of the door is secured, is provided with a sprocket 22 which is similar to the sprocket I9. A collar 23 is secured on the shaft I8 outside of said sprocket. For transmitting a rotation to the sprocket 22 of the lower shaft from the sprocket I9 of the upper shaft when the hand lever 20 is swung, a drive chain 24 has one end secured to the upper sprocket at 25. The chain passes over the sprocket I9 on the outer side of said sprocket and then extends downwardly and around the sprocket 22 on the lower shaft I8. It is noted that the lower end of the chain passes around the inner side of the sprocket 22, as is clearly shown in Figure l, and said chain has its other end 26 secured to the sprocket 22.

The collar 2| of the hand lever 29 is provided with a radially extending arm 2i, while the collar 23 on the shaft I8 is formed with a similar arm 28. With the parts in the position shown in Figure l, the arm 21 is directed inwardly while the arm 28 is'directed outwardly, and these arms are connected to each other by a coiled spring 29 which, as shown in this figure, crosses the chain 24. The spring 29' is at all times under tension.

With the sections A and B in their vertical position (Figure 4) the door I6 is, of course, closed, and at this time the operating mechanism is in the position shown in Figure 1. The spring 29 is holding the sections in their vertical position because said spring is pulling the arm 21 downwardly and the arm 28 upwardly, whereby it is tending to rotate the shafts I! and I8 in a clockwise direction. At such time, the drive chain 24 is stretched to its full length with no slack therein.

When the hand lever 29 is swung downwardly, the upper shaft I! is rotated in a counterclockwise direction and since the sprocket I9 is secured to said shaft, said sprocket is also rotated in this direction. As the sprocket I9 rotates the end 25 of the chain which is secured to said sprocket moves upwardly relative to its position in Figure 1. This causes a portion of the chain to leave the teeth of the sprocket I9 and thus create a slackin said chain between the sprocket I9 and the sprocket 22. However, as the hand lever 29 is swung downwardly the arm 27 is at the same time swung upwardly. This arm is connected by means of the coiled spring 29 with the arm 28 of the collar 23 on the lower shaft I8. Therefore, as the lever 26 moves clownwardly and the arm 21 upwardly, the arm 26 is also pulled upwardly because of the coiled spring. Upward movement of the arm 28 imparts a rota tion to the shaft I8 and the sprocket 22. The rotation of the sprocket will immediately take up any slack in the chain 24 to keep the same taut at all times. From the above, it will be seen that the swinging of the hand lever 2f will rotate the upper shaft I! ma counter-clockwise direction and will at the same time, rotate the lower shaft I8 in a clockwise direction. Such rotation of the shafts I1 and I 8 will cause the sections A and B of the door I IS to be swung inwardly to an open position. I

When it is desired to return the sections to a vertical position so as to close the door, the lever 29 is swung upwardly so as to rotate the sprocket I9 and shaft H in a clockwise direction. As this occurs, the arm 21 swings downwardly to relieve the tension on the coiled spring 29'. As the sprocket I9 rotates in a clockwise direction, it will impart a counter-clockwise rotation to the sprocket 22 through the medium of the drive chain 24. This will, of course, rotate the shaft I8 in a counter-clockwise direction which will swing the section B to its vertical position.

Due to the sprocket and chain connection therebetween, it will be obvious that both sprockets are rotated the same number of de grees and, therefore, the same amount of rotation is imparted to the shafts I7 and I8. However, since the shaft I3 is located forwardly of the shaft I I in a vertical plane, the section B is swung into engagement with the section A and is placed under a sli ht tension, whereby a positive engagement between the overlapping ends of the sections is obtained. The sections of the door are held in their vertical position by the coiled spring 25 which constantly exerts its pressure to hold said sections in this position. It is noted that due to temperature changes or other causes, there may occur slight variations in the length of the chain 24. Such variations will not affect the operation of the mechanism, as the coiled spring 29 will immediately compensate for any such condition. The spring 29 not only aids in holding the door in its closed position, but also acts to swing the lower section B to its open position whenever the hand lever is swung to create a slack in the chain 24, as has been explained. The mechanism is very simple and rugged in construction and has no parts which need constant adjustment. The action when the hand lever 20 is operated is positive so that the doors may be quickly moved from an open to a closed position, or vice versa.

What I claim and desire to secure by Letters Patent is:

1. An operating mechanism for a door having a pair of swinging sections arranged to move into overlapping engagement including, a rotatable shaft on which one of the sections is mounted, means for rotating said shaft to swing said section, a sprocket fastened on said shaft, a second rotatable shaft for supporting the other section of the door, a sprocket fastened on said shaft, a flexible connection between said sprockets, and resilient means separate from the connection and fastened to said shafts for connecting the shafts and co-acting with the connection to impart a rotation to the second shaft when the first shaft is rotated.

2. An operating mechanism for a door having a pair of swinging sections arranged to move into overlapping engagement including, a rotatable shaft on which one of the sections is mounted, means for rotating said shaft to swing said section, a sprocket fastened on said shaft, a second rotatable shaft for supporting the other section of the door, a sprocket fastened on said shaft, a flexible connection between said sprockets, and resilient means connecting the shafts free from the flexible connection and co-acting with the connection to impart a rotation to the second shaft when the first shaft is rotated, said means exerting its pressure to hold the sections in overlapping engagement with each other when the door is closed.

3. An operating mechanism for a door having a pair of swinging sections arranged to move into overlapping engagement including, a rotatable shaft on which one of the sections is mounted, means for rotating said shaft to swing said section, a sprocket fastened on said shaft, a second rotatable shaft for supporting the other section of the door, a sprocket fastened on said shaft, a flexible connection between said sprockets, a radial arm on each shaft, and a coiled spring connecting the arms to urge them toward each other and co-acting with the connection to impart a rotation to the second shaft when the first shaft is rotated.

4. An operating mechanism for a door having a pair of swinging sections arranged to move into overlapping engagement including, a rotatable shaft on which one of the sections is mounted, means for rotating said shaft to swing said section, a sprocket fastened on said shaft, a second rotatable shaft for supporting the other section of the door, a sprocket fastened on said shaft, a flexible connection between said sprockets, a radial arm on each shaft, and a coiled spring connecting the arms to urge them toward each other and co-acting with the connection to impart a rotation to the second shaft when the first shaft is rotated, said connection and spring being arranged so as to rotate the shafts in opposite directions.

5. An operating mechanism for a door having a pair of swinging sections including, a rotatable shaft on which one of said sections is mounted, means for rotating said shaft to swing the section, a second rotatable shaft on which the second section is mounted, a flexible connection having one end secured to one of the shafts with the other end fastened to the other shaft whereby rotation of one will impart rotation to the other, and an elongate coiled spring having its ends-connected with the shafts and being entirely independent of the flexible connection associated with the flexible connection and having sufiicient length to compensate for variations in said connection due to expansion and contraction under a relatively wide range of temperatures.

6. An operating mechanism for a door having a pair of swinging sections including, a rotatable shaft on which one of the sections is mounted, means for rotating said shaft to swing said section, a second rotatable shaft for supporting the other section of the door, a flexible chain between the shafts, and a coiled spring separate from the connection and having its ends connected with the shafts so as to urge the shafts toward a rotation in one direction, said connection and spring coacting to impart rotation to the second shaft when the first shaft is rotated, whereby the door sections are swung simultaneously.

7. An operating mechanism for a door having a pair of swinging sections including, a rotatable shaft on which one of the sections is mounted, manually operable means for rotating the shaft to swing said section, a second rotatable shaft for supporting the other section of the door, a flexible connection having one end secured to one of the'shafts with its other end secured to the other shaft whereby a rotation of one shaft will impart rotation to the other, and a coiled spring having its extremities secured to the shafts independently of the flexible connection, whereby said spring tends to rotate the shafts in a direction holding the flexible connection taut and also serves to compensate for expansion and contraction of said connection.

LOUIS D. HOULIS. 

